I had a custom oil tank made with all hoses entering at the bottom of the tank. The return and vent lines have stand pipes so they enter the very upper part of the tank. I also added a tank drain plug, which my 2012 car did not have originally.

The new tank is also longer, giving more oil capacity, and made of heavier gauge alloy so more robust. The three smaller black caps that appear to be on the upper side of the tank (1rst photo) are actually the brake/clutch reservoir caps, btw.

Anyone who custom makes oil tanks for motorcycles should be able to help you here.

[Linked Image]
[Linked Image]

Steve
Late 2012 M3W